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树枝状大分子是一种具有精确三维结构的纳米材料。目前,对于树枝状大分子的研究,逐渐从合成和表征各式各样的树枝状大分子转向到对其特殊功能和应用的研究。传统的荧光成像探针大多数为小分子化合物,其发展受到特异性低、稳定性差、停留时间短、可修饰基团少和毒性大等缺点的限制。树枝状大分子具备独特的分子结构如大量可设计性的末端官能团和广阔的分子内空腔以及选择多样化的优势,使其在荧光生物成像领域中有良好的应用前景。本文重点介绍了基于树枝状大分子的有机荧光探针和量子点探针在生物成像方面最新的研究进展。 相似文献
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三维光学断层成像(Three Dimensional Optical Tomography Imaging)是以光学探针标记的分子或细胞为成像源,在外部光源的激发下产生发射光,通过测量组织边界处的光强,结合光子在组织中的传播模型,来重建出组织内部发射光分布图像以及组织光学参数。三维光学断层成像能够提供目标物在生物体内的分布信息,克服平面成像的局限性。因此,在肿瘤检测、基因表达、蛋白质分子检测、揭示机体功能变化等方面有着很大的应用潜力。本文总结了光学相干断层成像(Optical Coherence Tomography,OCT)、荧光分子断层成像(Fluorescent Molecular Tomography,FMT)、生物自发光断层成像(Bioluminescence Tomography,BLT)、切伦科夫荧光断层成像(Cerenkov Luminescence Tomography,CLT)等三维光学断层活体成像技术的新进展,分析了其在实际应用中所面临的技术挑战并探讨了相应的解决方案。 相似文献
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随着科技的发展和社会的进步,食品安全问题越来越受到关注。糖精钠作为一种食品添加剂,其非法添加事件时有发生,因此,有必要找到一种快速准确检测糖精钠的方法。荧光分子探针因具有灵敏度高、选择性好、响应时间短的优点,其在分析化学检测中的应用越来越广泛。本文设计并合成了一种含蒽荧光团的氮杂15-冠-5化合物,利用分子识别的原理,该目标化合物能够特异性识别溶液中的糖精钠,使溶液的荧光强度发生变化,具有肉眼可见、易于观察的特点,该方法为食品中糖精钠的快速检测提供了一种可行的手段。 相似文献
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《化学:亚洲杂志》2017,12(19):2533-2538
Designing two‐photon probes for precise labeling of lipid droplets (LDs) and monitoring LD dynamics in adipocytes is of great significance to understand LD homeostasis. We herein report that a luminescent metal complex LD‐TPZn can specifically image LDs in adipose cells and tissue using one‐ or two‐photon fluorescence microscopy. Importantly, LD‐TPZn exhibited higher specificity to LDs than the commercial dyes Nile Red and Bodipy 493/503, probably due to different cellular uptake pathways, that is, clathrin‐mediated endocytosis and non‐selectively passive diffusion, respectively. More importantly, LD‐TPZn can be applied as a two‐photon LD probe to image adipose tissue, one of the most challengeable tissues for traditional one‐photon fluorescence microscope imaging due to the strong light scattering. Most importantly, LD‐TPZn can be used to monitor LD growth during adipogenesis of preadipocytes, which is highly desirable to unravel the relationship between LD homeostasis and metabolic diseases. 相似文献
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Semiconductor quantum dots as biological imaging agents 总被引:2,自引:0,他引:2
Green M 《Angewandte Chemie (International ed. in English)》2004,43(32):4129-4131
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Dr. Yusuke Takezawa Shiori Sakakibara Prof. Dr. Mitsuhiko Shionoya 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(67):16626-16633
DNA three-way junction (3WJ) structures are essential building blocks for the construction of DNA nanoarchitectures. We have synthesized a bipyridine (bpy)-modified DNA 3WJ by using a newly designed bpy-modified nucleoside, Ubpy- 3 , in which a bpy ligand is tethered via a stable amide linker. The thermal stability of the bpy-modified 3WJ was greatly enhanced by the formation of an interstrand NiII(bpy)3 complex at the junction core (ΔTm=+17.7 °C). Although the stereochemistry of the modification site differs from that of the previously reported bpy-modified nucleoside Ubpy- 2 , the degree of the NiII-mediated stabilization observed with Ubpy- 3 was comparable to that of Ubpy- 2 . Structure induction of the 3WJs and the duplexes was carried out by the addition or removal of NiII ions. Furthermore, NiII-mediated self-sorting of 3WJs was performed by using the bpy-modified strands and their unmodified counterparts. Both transformations were driven by the formation of NiII(bpy)3 complexes. The structural induction and self-sorting of bpy-modified 3WJs are expected to have many potential applications in the development of metal-responsive DNA materials. 相似文献
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de Hatten X Cournia Z Huc I Smith JC Metzler-Nolte N 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(29):8139-8152
The increasing importance of hydrogenase enzymes in the new energy research field has led us to examine the structure and dynamics of potential hydrogenase mimics, based on a ferrocene-peptide scaffold, using molecular dynamics (MD) simulations. To enable this MD study, a molecular mechanics force field for ferrocene-bearing peptides was developed and implemented in the CHARMM simulation package, thus extending the usefulness of the package into peptide-bioorganometallic chemistry. Using the automated frequency-matching method (AFMM), optimized intramolecular force-field parameters were generated through quantum chemical reference normal modes. The partial charges for ferrocene were derived by fitting point charges to quantum-chemically computed electrostatic potentials. The force field was tested against experimental X-ray crystal structures of dipeptide derivatives of ferrocene-1,1'-dicarboxylic acid. The calculations reproduce accurately the molecular geometries, including the characteristic C2-symmetrical intramolecular hydrogen-bonding pattern, that were stable over 0.1 micros MD simulations. The crystal packing properties of ferrocene-1-(D)alanine-(D)proline-1'-(D)alanine-(D)proline were also accurately reproduced. The lattice parameters of this crystal were conserved during a 0.1 micros MD simulation and match the experimental values almost exactly. Simulations of the peptides in dichloromethane are also in good agreement with experimental NMR and circular dichroism (CD) data in solution. The developed force field was used to perform MD simulations on novel, as yet unsynthesized peptide fragments that surround the active site of [Ni-Fe] hydrogenase. The results of this simulation lead us to propose an improved design for synthetic peptide-based hydrogenase models. The presented MD simulation results of metallocenes thereby provide a convincing validation of our proposal to use ferrocene-peptides as minimal enzyme mimics. 相似文献
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Dr. Xiao-Lu Wang Dr. Jia-Yue Tian Xuan-Chen Guo Prof. Dr. Fu-Qiang Zhang Dr. Linfeng Liang Prof. Dr. Xian-Ming Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(11):3753-3760
Dimethyl sulfoxide (DMSO) is a universally used solvent in various synthetic reactions, and trace amounts of DMSO residual are often seen on the surface of chemical product. It is difficult to quickly determine whether the residual DMSO is washed completely. This work reports a CdII metal–organic framework (MOF) SXU-4 which can detect trace amounts of DMSO in various solvents. Fluorescence experiments reveal its turn-on fluorescence effect toward DMSO with high selectivity and sensitivity, indicating that it can be used as an effective luminescent probe for rapid chemical product purity detection by testing the washing solution. Crystallographically characterized DMSO loaded SXU-4 (DMSO@ SXU-4 ), in combination with computational results uncover that the enhanced DMSO–MOF conjugation through multiple DMSO–MOF supramolecule interactions and charge rearrangement are the main causes of fluorescence intensification. 相似文献
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Oxygen imaging of biological cells and tissues is becoming increasingly important in cell biology and in the pathophysiology of various hypoxia-related diseases. The optical oxygen-sensing method using luminescent probes provides very useful, high spatial resolution information regarding oxygen distribution in living cells and tissues. This review focuses on recent advances in biological oxygen measurements based on the phosphorescence quenching of probe molecules by oxygen, and on hypoxia-sensitive fluorescent probes. Special attention is devoted to metal complex probes, Pt(II)- and Pd(II)-porphyrins, Ru(II) complexes, and Ir(III) complexes. Current knowledge regarding the mechanism of phosphorescence quenching of metal complexes by oxygen is described in relation to the oxygen sensitivity of the probes, and recent advances in optical oxygen probes and detection techniques for intracellular and tissue oxygen measurements are reviewed, emphasizing the usefulness of chemical modifications for improving probe properties. Tissue oxygen imaging and hypoxic tumor imaging using these metal complex probes demonstrate the vast potential of optical oxygen-sensing methods using luminescent probes. 相似文献
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Philip M. Punt Prof. Dr. Guido H. Clever 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(61):13987-13993
Two types of imidazole ligands were introduced both at the end of tetramolecular and into the loop region of unimolecular DNA G-quadruplexes. The modified oligonucleotides were shown to complex a range of different transition-metal cations including NiII, CuII, ZnII and CoII, as indicated by UV/Vis absorption spectroscopy and ion mobility mass spectrometry. Molecular dynamics simulations were performed to obtain structural insight into the investigated systems. Variation of ligand number and position in the loop region of unimolecular sequences derived from the human telomer region (htel) allows for a controlled design of distinct coordination environments with fine-tuned metal affinities. It is shown that CuII, which is typically square-planar coordinated, has a higher affinity for systems offering four ligands, whereas NiII prefers G-quadruplexes with six ligands. Likewise, the positioning of ligands in a square-planar versus tetrahedral fashion affects binding affinities of CuII and ZnII cations, respectively. Gaining control over ligand arrangement patterns will spur the rational development of transition-metal-modified DNAzymes. Furthermore, this method is suited to combine different types of ligands, for example, those typically found in metalloenzymes, inside a single DNA architecture. 相似文献